The invention relates to an axle stub bearing unit for a bearing point of an axle stub of a steerable axle of a vehicle, with a radial bearing, which is constructed as a needle bearing, and a separate axial bearing, which is constructed as a sliding bearing, wherein these bearings are accommodated in a cup-shaped bush.
Axle stub bearing units are used in steerable front axles of commercial vehicles and buses. So that these vehicles can be steered, the wheels or wheel heads of at least one vehicle axle must be supported so that they can rotate about an axle stub pin. The axle stub is connected to the vehicle by the vehicle axle. In the axle stub, the axle stub pin is installed protected from torsion. The wheel head and the wheel are supported by an upper and lower bearing so that they can rotate about the axle stub pin. Both axle stub bearings with separate radial and axial bearings and also combined radial-axial bearings are known. The upper and lower radial bearings can be constructed as sliding bearings, but typically as needle bearings. The radial bearing receives radial forces generated, e.g., when driving in a curve. The lower axial bearing can be constructed, e.g., as sliding bearings and receives the weight forces of the vehicle or forces generated during driving. The upper axial bearing, which can be constructed as a sliding bearing with a thrust washer, receives axial forces generated during driving, for example, when the vehicle is driving over uneven ground, a pothole, or a curb.
From DE 197 38 113 A1, a front axle for a truck or minivan with steerable, non-driven wheels is provided. There, in FIG. 2 an axle stub bearing unit is shown, in which, instead of cylinder or tapered rollers, a sliding bearing is provided, which comprises a pressure ring that is supported on a bearing ring washer in a sliding manner. This conventional axle stub bearing unit, however, has the disadvantage that it has a relatively complicated construction. For sealing the axial bearing, a sliding sleeve is provided there, which requires increased structural effort. In addition, the pressure ring is a solid component, which requires a large installation space and leads to relatively high costs.